Diferentially or Differentially: How To spell?
The word Diferentially is misspelled against Differentially, an adverb meaning "In the way of differentiation."
Differentially has double "ff" is mispronounced as "f"Remember double 'FF' in between the strings Di & erentially which should not be misspelled with single 'F'
Wrong Spelling:  Di-f-erentially  Correct Spelling:  Di-ff-erentially 
Find more wrongly spelled words of Differentially to spell it well.